Representative among main diseases of people these days is cancer. Studies on cancer are actively ongoing, particularly in the areas of high-prevalence cancers including lung cancer, liver cancer, stomach cancer, etc., but there are fewer studies being conducted on low-prevalence cancers including esophageal cancer, colorectal cancer, pancreatic cancer, etc.
In particular, pancreatic cancer usually does not cause recognizable symptoms in its early stages, and the disease is typically not diagnosed due to its minor symptoms such as pain, weight loss, etc., until it has spread beyond the pancreas itself to the whole body. Moreover, pancreatic cancer is generally poor in survival rate, and thus periodical diagnosis is very important. Clinical symptoms of pancreatic cancer are, in most part, slowly exposed, and patients with pancreatic cancer most commonly suffer from feebleness, anorexia, and weight loss. Found to have a five-year survival rate of 1-4% with a median survival time of 5 months, pancreatic cancer is very fatal and is the poorest in prognosis among human cancers. After diagnosis, it is found that 80-90% of people are impossible to treat by hopeful curative resection. This is one of the main reasons for the generally highly poor prognosis. Pancreatic cancer is predominantly treated with chemotherapy. Therefore, in comparison to other cancers, there is a desperate need for an early diagnosis method of pancreatic cancer. Although known so far to be useful in treating pancreatic cancer, several anticancer agents including 5-fluorouracil, gemcitabine, and tarceva, exhibit very low curative effects and a reaction rate of only around 15% for cancer treatment. These situations suggest there is a pressing request for more effective early diagnosis and therapy for pancreatic cancer whereby the prognosis can be improved.
Diagnosis of pancreatic cancer is determined upon hematologic examination (CA19-9), gastrointestinography and duodenography with X-ray contrast media, cholangiography through the skin and the liver, or endoscopic retrograde cholangiopancreatography. Many disease lesions can be detected by such methods, but currently, ultrasonography and computed tomography are the most preferred. More deliberate biopsy methods might result in relatively more accurate outcomes. The diagnosis methods described above are used because they are generally accurate; however, subjects are unwilling to undergo examination because such diagnosis methods are uncomfortable or painful. Hence, there is need for method of diagnosing pancreatic cancer conveniently and rapidly.
In this context, Korean Patent No. 10-0819122 discloses technologies using various pancreas cancer markers including matrilin, transthyretin, and stratifin. In addition, Korean Patent Unexamined Application Publication No. 2012-0082373 describes the diagnosis of pancreatic cancer by using various makers for pancreatic cancer. KR2009-0003308 discloses diagnosis of pancreatic cancer through the detection of an expression level of REG4 in a blood sample from a subject. KR 2012-0009781A describes an analysis method for measuring an XIST RNA expression level in a cancer tissue from a subject, whereby information on the onset of pancreatic cancer in the subject can be provided. KR2007-0119250A discloses a family of new LBFL313 genes that are expressed in different patterns between normal pancreatic tissues and pancreatic cancer tissues. US 2011/0294136A1 discloses a diagnosis method of pancreatic cancer using biomarkers including keratin 8 protein. However, diagnostic efficiency and accuracy greatly differ from one marker to another. Therefore, there is a pressing need for an excellently efficient marker and a diagnosis method using the same.
The present inventors had made an effort to develop a maker being useful for diagnosing a pancreatic cancer in an early stage, and thus identified proteins over-expressed or under-expressed in pancreatic cancer, and completed the present invention by confirming that the pancreatic cancer could be easily diagnosed with the proteins.